A dc power supply has a no-load voltage of 30V, and a full-load voltage of 25 V at a full-load current of 1A. Its output resistance and load regulation, respectively are

A bipolar junction transistor amplifier circuit is shown in the figure. Assume that the current source I_bias is ideal, and the transistor has very large$$\beta ,\,\,{r_{b\,\,}} = \,\,0,$$ and the $${r_0}\, \to \,\infty $$.

Determine the ac small-signal mid-band and voltage gain $$\left( {{V_o}/{V_s}} \right),$$ input resistance (R₁, and output resistance (R₀) of the circuit. Assume $${V_{T\,\,}} = \,\,26\,mV.$$

An NPN transistor (with $${C_\pi }\,\, = \,\,0.3\,\,$$ pf) has a unity gain cutoff frequency $${f_T}$$ of 400 MHz at a DC-bias current I_c = 1mA. The value of its $${C_\mu }$$ (in pf) is approximately $$\left( {{V_T}\, = \,26\,mV} \right)$$.

An amplifier is assumed to have a single pole high frequency transfer function. The rise time of its output response to a step function input is 35 nsec. The upper 3 dB frequency (in MHz) for the amplifier to a sinusoidal input is approximately at